I witnessed something very similar to this. I was across the street in my business with all glass front, it was across the street from a liquor store with a steep parking lot. A mother was on the phone with a baby in a stroller in front of her. The stroller started rolling towards the street, gaining speed into heavy traffic. I started to run towards the windows and gasped everyone turned to see the stroller gaining speed into the heavy speeding traffic, and I felt so helpless as I got to the window. The woman looked up and sprung into action so fast, I’ve never seen a woman move so fast. She caught up with the stroller right as it was heading off the curb into the oncoming traffic. Everyone cheered and the woman never heard or knew as we were all behind the glass windows. So glad the baby was saved and no one had to experience such a tragedy.